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Showing 1 to 20 of 34 for “"Loss Factor"”.
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Dielectric loss determination using perturbation
… used to estimate the dielectric constant and loss factor over a wide range of frequencies of a dielectric material which fills the cavity structure [Saed, 1987]. A full field analysis is used to compute the effective complex permittivity of the sample material based on reflection coefficient …
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Passive Viscoelastic Constrained Layer Damping Application for a Small Aircraft Landing Gear System
… to establish approximate storage modulus and loss factor data at varying loading frequencies. The three viscoelastic polymers having the highest loss factor to shear modulus ratio were chosen and tested using a cantilever beam system. A Ross, Kerwin, and Ungar analysis was used to predict the …
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Evaluation of analytical and experimental methods to predict constrained layer damping behavior
… parameters, and evaluation of experimental loss factor estimation techniques. Model comparison for damping estimation and resonant frequency prediction was performed between finite element analysis (FEA) Ross, Kerwin, and Ungar theory (RKU), developed moment predicted loss factor, and …
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Gluten-free bread : characterization and development of pre- and post- baked gluten free bread
… of xanthan gum were found to decrease the loss factor thus strengthening the elastic properties of the dough, elongating the linear viscoelastic region and increasing the viscosity of the dough. Furthermore, the xanthan gum samples were not independent of frequency and the loss factor …
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A methodology for developing high damping materials with application to noise reduction of railway track
… materials should have a high<br/>damping loss factor, but this is inevitably linked to a strong temperature-dependence<br/>of the dynamic properties. A methodology is developed that allows a material to be formulated<br/>for a particular damping application where temperature-dependence has …
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Experimental Study on Viscoelastic Properties and Fracture Characteristics in Polymers
… />2. To determine the internal friction (loss factor) of polymers under periodic loading condition;<br />3. To determine the delayed time or life time on fracture of the polymer under constant loading ; and<br /> 4. To verify the relationship, theoretically predicted, between the time to …
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Static and Dynamic Characterisation of Flax Fibre-reinforced Polypropylene Composites
… was used to estimate the natural frequency and loss factor. The single-degree-of-freedom circle-fit method and the Newton’s divided differences formula were used to estimate the natural frequencies as well as the loss factors. The damping estimates were also investigated using a “carpet” plot. …
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On the damping of flexural plate vibrations by the application of viscoelastic layers
… and real parts of D*, representing the so-called loss factor. The problem of how to apply uniformly a given quantity (weight) of viscoelastic material to a base plate in order to achieve the greatest composite loss factor is considered. It is found, contrary to what had heretofore been believed, …
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A Study of Distributed Active Vibration Absorbers (DAVA)
… while increasing the DAVA foam layer loss factor increased the attenuation, and decreasing the foam loss factor resulted in decreased attenuation. Finally, by varying the area of the single optimum DAVA that passively minimizes the sound power of the plate, it has been shown that both …
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Evaluation and design of polymer systems for enhanced microwave heating
… transmission/reflection technique. The electric loss factor of the epoxy system continuously decreased during cure. Results for the microwave heating of the polypropylene-iron composites show that heating is enhanced with increased iron concentration and smaller iron particle size, although the …
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Passive Damping in Stiffened Structures Using Viscoelastic Polymers
… modulus in the base and constraining layers. The loss factor was calculated by modal strain energy method, and by solving a complex eigenvalue problem. The efficiency of the modal strain energy method was tested for different loss factors in the core layer. Complex mode shapes of the beam were …
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Structural vibration damping using lightweight, low-wave-speed media
… We develop analytical approximations for the loss-factor in the structural modes of cylindrical shells and Timoshenko beams and attain predictions in good agreement with measurements. For more complicated geometries, it is often necessary to employ a finite element model to predict the …
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The surface propagation of ground vibration
… hysteric internal damping characterised by a loss factor. For an infinite strip load, which reduces the problem to two dimensions, three ground structures have been considered: a half-space, a layer over an inflexible half-space, and a layer over a flexible half-space of different material …
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Application of Alternative Technologies to Eliminate <i>Vibrios </i> spp. in Raw Oysters
… with temperature. The dielectric constant and loss factor of oysters were determined by an open-ended coaxial line probe connected to a network analyzer at frequency of 30 MHz to 3000 MHz from 1 to 55 °C. The penetration depth of dielectric heating was calculated to be 1.1 cm with the …
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Development of switchable planar reflectors for beam shaping realization
… characterization for bandwidth and reflection loss optimization of different slot embedded patch configurations was done based on the scattering parameter measurements. Maximum frequency variation of 2.56GHz with dynamic phase range of 346 ̊ in X-band was demonstrated by rectangular slots in …
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Dielectric measurement based microstrip transmission line
… properties of dispersive material including its loss factor material based on Kramers-kronig relationship.
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The prediction of flow patterns, liquid holdup and pressure losses occurring during continuous two-phase flow in horizontal pipelines
… predicted. The third correlation is an "energy loss factor" correlation which, when used with the two-phase power balance developed in this study, permits pressure losses to be predicted. The principle of dimensional analysis is used and therefore all of the correlations are dimensionless. A …
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Coaxial contrarotating twin rotor aerodynamics
… and replace the arbitrary application of a tip loss factor. Using this combined approach, named Vortex-Strip theory, the full interference effects between the two rotors of a hovering CCTR have been successfully modelled. By a similar approach, a Vortex-Glauert theory has been developed to model …
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Investigation of Processing Conditions and Viscoelastic Properties on Frictional Sliding Behavior of Unidirectional Carbon Fiber Epoxy Prepreg
… complex viscosity (η*), storage modulus (G'), loss modulus (G"), and loss factor (tan δ) were used to determine the critical transition events (such as gelation) during cure. An understanding of changes in viscoelastic properties as a function of time, temperature, and cure provides insight for …
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Characterization of the Viscoelastic Fracture of Solvated Semi-Interpenetrating Polymer Network Silicone Hydrogels
… master curves and corresponding thermal shift factors of such properties as shear relaxation modulus, dynamic moduli, and the loss factor. Concurrently, the cohesive fracture properties were studied by utilizing a "semi-infinite" strip geometry under constrained tension in which thin …
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